Massage ball



FIG. 1 is a perspective view of the massage ball;

FIG. 2 is a front elevation view of the invention;

FIG. 3 is a left side view of the invention, the right side view being a mirror image;

FIG. 4 is a rear elevation view of the invention;

FIG. 5 is a top plan view of the invention; and,

FIG. 6 is a bottom plan view of the invention. 

The ornamental design for a massage ball, as shown and described. 